Abstract: A mounting plate for locating under a superconducting magnet structure, between the superconducting magnet structure and a supporting surface of a mobile carrier, is controllable between two different states. In a first state, the mount provides rigid attachment and precise location of the superconducting magnet structure onto the supporting surface of the mobile carrier. In a second state, the mount provides vibration isolation between the superconducting magnet and the mobile carrier.

Abstract: Device for generating an orientable and locally uniform magnetic field, including N?3 identical assemblies of cylindrical coils, each assemblies having a first and a second coil, the coils being coaxial with an axis oriented along a direction z and arranged symmetrically on either side of the plane, with a gap in the axial direction, the assemblies arranged such that their outlines in a plane xy perpendicular to the z-axis are regularly spaced along a circle of center O and of radius a0>0, so to leave a central free space. A supply system supplies the coils with a current set to obtain, at the center of the device, a magnetic field having the desired orientation. The device may include two pairs of cylindrical coils having a common axis oriented in said z-direction and passing through the center of the circle, these coils being arranged symmetrically on either side of said xy-plane.

Abstract: In a MRI system housed within a room there is provided a movable magnet and additional components for other procedures on the patient, a control system is provided for the relative movement of the magnet and components. This includes a plurality of magnetic field sensors mounted on the components for measuring the magnetic field at the location of the component and an optional camera positioning system so that the control system can estimate relative positions of the components relative to the magnet from the sensed field strengths from the set of sensors to avoid collisions during the movements.

Abstract: A system and method for reducing MRI-generated acoustic noise is disclosed. A system control of an MRI apparatus causes a plurality of gradient coils and an RF coil assembly in the MRI apparatus to generate pulse sequences that each cause an echo train to form and acquire blades of k-space data of the subject of interest from the pulse sequences, with the blades being rotated about a section of k-space compared to every other blade. The system control also causes the plurality of gradient coils to generate gradient pulses in each pulse sequence having an optimized gradient waveform that reduces an acoustic noise level generated thereby and causes the RF coil assembly to generate a 180 degree prep pulse subsequent to generation of an RF excitation pulse and prior to generation of a first RF refocusing pulse, the 180 degree prep pulse minimizing echo spacing in the echo train.

Abstract: Methods of fastening a cage with a fastening system in an MRD. One method includes: assembling: a plurality of pole pieces; a plurality of side magnets, the side magnets substantially enclosing the pole pieces and thereby defining a magnetic envelope and enclosed volume therein; a plurality of side walls, the side walls substantially enclosing the side magnets; a plurality of face walls and a plurality of fastening rods; and passing a plurality of fastening rods through at least one of the side magnets and at least one of the pole pieces and fastening them in an effective measure, such that the rods physically interconnects at least one pair of side walls.

Abstract: A method is disclosed for imaging a part region of an examination object in a magnetic resonance system. In an embodiment, a first and second gradient field are respectively created such that, at a respective first and second position at the edge of the field of view, a distortion caused by a non-linearity of the respective first and second gradient field, and a distortion caused by a B0 field inhomogeneity, cancel each other out. By way of the respective first and second gradient, respective first and second magnetic resonance data which contains the respective first and second position are acquired. A first and second respective readout direction, in which the respective first and second magnetic resonance data are acquired, are selected as a function of a location of the respective first second position are acquired. From the magnetic resonance data, an image of the part region is defined.

Abstract: A gradient coil arrangement for use in a magnetic imaging system, the imaging system being for generating a magnetic imaging field in an imaging region provided in a bore. The coil arrangement includes a first portion having a substantially cylindrical shape for positioning in the bore, a second portion extending outwardly from an end of the first portion, the second portion being for positioning outside the bore and at least one coil for generating a gradient magnetic field in the imaging region, the at least one coil having a first part provided on the first portion and a second part provided on the second portion.

Abstract: This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a nuclear magnetic resonance device includes a support frame, a first magnet connected to the support frame, a second magnet connected to the support frame in a manner such that the second magnet is disposed within the magnetic field of the first magnet and a magnetic attraction exists between the first magnet and the second magnet, and a spacer disposed between the first magnet and the second magnet. The spacer is configured to maintain a space between the first magnet and the second magnet.

Abstract: Systems and methods for the delivery of linear accelerator radiotherapy in conjunction with magnetic resonance imaging in which components of a linear accelerator may be placed in shielding containers around a gantry, may be connected with RF waveguides, and may employ various systems and methods for magnetic and radio frequency shielding.

Abstract: A radiation therapy system comprises a magnetic resonance imaging (MRI) system combined with an irradiation system, which can include one or more linear accelerators (linacs) that can emit respective radiation beams suitable for radiation therapy. The MRI system includes a split magnet system, comprising first and second main magnets separated by gap. A gantry is positioned in the gap between the main MRI magnets and supports the linac(s) of the irradiation system. The gantry is rotatable independently of the MRI system and can angularly reposition the linac(s). Shielding can also be provided in the form of magnetic and/or RF shielding. Magnetic shielding can be provided for shielding the linac(s) from the magnetic field generated by the MRI magnets. RF shielding can be provided for shielding the MRI system from RF radiation from the linac.

Abstract: A method of magnetic resonance imaging includes performing a first magnetic resonance scan sequence which saves a data store, and performing a second magnetic resonance scan sequence which uses a data store from the first magnetic resonance scan sequence. A magnet (10) generates a B0 field in an examination region (12), a gradient coil system (14, 22) creates magnetic gradients in the examination region, and an RF system (16, 18, 20) induces resonance in and receives resonance signals from a subject in the examination region. One or more processors (30) are programmed to perform a magnetic resonance pre-scan sequence to generate pre-scan information, perform a first sequence to generate first sequence data, refine the pre-scan information with the first sequence data, perform a second imaging sequence to generate second sequence data. Further, the second sequence data is either reconstructed using the refined pre-scan information or performed using the refined pre-scan sequence information.

Abstract: An NMR method and apparatus for analyzing a sample of interest applies a static magnetic field together with RF pulses of oscillating magnetic field across a sample volume that encompasses the sample of interest. The RF pulses are defined by a pulse sequence that includes a plurality of measurement segments configured to characterize a plurality of relaxation parameters related to relaxation of nuclear magnetization of the sample of interest. Signals induced by the RF pulses are detected in order to derive the relaxation parameters. The measurement segments of the pulse sequence include at least one first-type measurement segment configured to characterize relaxation of spin-lattice interaction between nuclei of the sample of interest in a rotating frame (T1?) at a predefined frequency. The T1? parameter can be measured in conjunction with the measurement of other relaxation and/or diffusion parameters as part of multidimensional NMR experiments.

Abstract: An MRI system has a cylindrical superconducting magnet assembly contained in a bore tube of a cylindrical vacuum vessel (OVC), and a gradient coil assembly situated within the OVC bore tube. In an imaging region within a bore of the gradient coil assembly, the magnet assembly produces a magnetic field that is subject to drift during operation of the MRI system. Compensating material is located at a radial position between the imaging region and the magnet in a location that will be heated over a range of temperatures during operation of the MRI system. The compensating material is adjustable between two magnetic phases in response to an applied physical characteristic, which is selectively applied thereto so as to change the compensating material from a first magnetization to a second magnetization, and thereby compensate the drift.

Abstract: A magnetic resonance imaging (MRI) system includes a main magnet configured to generate a static magnetic field, a gradient coil configured to generate a gradient magnetic field, and a radio frequency (RF) coil including a plurality of RF coils corresponding to volumes representing target regions of a subject.

Abstract: A magnetic resonance imaging configuration to straighten and otherwise homogenize the field lines in the imaging portion, creating improved image quality. Through use of calibrated corrective coils, magnetic field lines can be manipulated to improve uniformity and image quality. Additionally, when the apparatus is composed of non-ferromagnetic materials, field strengths can be increased to overcome limitations of Iron-based systems such as by use of superconductivity. A patient positioning apparatus allows multi-positioning of a patient within the calibrated and more uniform magnetic field lines.

Abstract: A system and method for simultaneously generating spectral images and spatial images of a subject using a magnetic resonance imaging (MRI) system includes acquiring MR image data using a k-space sampling trajectory. The k-space sampling trajectory is designed to spatially oversample to elicit phase differences between oversampled points. The MR image data is jointly reconstructed into spatial and spectral images by resolving spatial information from spatial encoding associated with each of the oversampled points and resolving spectral information from the phase differences between the oversampled points.

Abstract: The invention relates to an electromagnet and a method manufacturing the same. The electromagnet includes a frame having a volume within, and a conductive wiring wound around the frame. In accordance with the invention the magnet includes at least two circular grooves having two walls parallel to the each other and perpendicular to the longitudinal axis of the frame, at least two wire stacks each including at least one substack, wherein the wire has a cross section, at least one of the walls separating the two circular grooves, and jump wiring interconnecting the stacks so that contributions from jump wires of the adjacent stacks to total axial directional current are cancelled in average by the current of the return current wire, such that their contribution to the resulting magnetic field at the sample volume is minimized.

Abstract: A gradient coil apparatus for a magnetic resonance imaging (MRI) system includes an inner gradient coil assembly and an outer gradient coil assembly disposed around the inner gradient coil assembly. The outer gradient coil assembly has an outer surface, a first end and a second end. The gradient coil apparatus also includes a force balancing apparatus disposed around the outer surface of the outer gradient coil assembly. In one embodiment, the force balancing apparatus includes an active force balancing coil disposed around the outer surface of the outer gradient coil assembly. In another embodiment, the force balancing apparatus includes a first passive conducting strip disposed around the first end of the outer gradient coil assembly and a second passive conducting strip disposed around the second end of the outer gradient coil assembly.

Abstract: In order to prevent quenching caused accidentally in a superconducting magnet, an MRI apparatus vibrates the superconducting magnet in order to prevent quenching of the superconducting magnet in a time period for which a predetermined imaging sequence is not executed (step 210). As a specific method, a gradient magnetic field may be generated by a gradient magnetic field coil for an imaging sequence of the MRI apparatus, or a gradient magnetic field may be generated using a gradient magnetic field coil for vibration provided apart from the gradient magnetic field coil for an imaging sequence. In addition, in a period for which the predetermined imaging sequence is not executed, a phantom may be imaged to prevent the quenching of the superconducting magnet.

Abstract: A magnetic resonance imaging apparatus includes a magnet having two poles and a wall connecting the poles; the poles delimiting a patient-imaging space; and a table which is slidably connected to one of the two poles between the two poles and which table extends substantially parallel to the two poles; a drive for displacing the table relative to the magnet; a lock for locking the table in a selected position relative to the magnet; a drive for rotating the magnet about the axis; the table connected to the magnet such that the table rotates with the magnet when the magnet rotates about the axis; the magnet and the table being rotatable from a position in which the poles and the table are horizontal to a position in which the table and the poles are vertical.

Abstract: A capillary cartridge assembly for positioning a sample fluid at a geometric center between juxtaposed pole pieces of a NMR magnet assembly for NMR analysis comprises a capillary captured in a channel in a printed circuit board assembly that is sized to fit between the pole pieces. The assembly includes a RF coil surrounding a portion of the capillary. Electric traces shaped to function as shim coils can be included in the printed circuit board. An end of the printed circuit board includes electrically conductive contacts that plug into a receptacle to connect the RF coil and traces to external electrical circuitry when the RF coil is in the geometric center. The capillary can be a continuous flow-through capillary or a closed cartridge.

Abstract: A magnetic resonance imaging (MRI) system magnet includes at least one main electromagnet winding disposed within a first radius of the magnet and at least one bucking electromagnet winding disposed within a second radius, larger than the first radius of the magnet and configured to provide self-shielding magnetic fields that substantially reduce fringe magnetic fields outside the magnet produced by the main electromagnet winding. The combination of magnetic fields produced by both the main and bucking electromagnet windings inside the magnet conform to MRI requirements within at least an imaging volume. The main and bucking electro-magnet windings are configured so as to create a net fringe field outside the magnet within the range of 50-100 gauss at a distance within a range of 3-5 meters axially and 2-3 meters radially from a center of the magnet.

Abstract: A phased array radio-frequency (RF) coil includes a cylindrical frame including a coaxial inner frame and a coaxial outer frame having different diameters; and vertical loop coils arranged in a circumferential direction of the cylindrical frame. Each vertical loop coil includes an inner conductor extending in a lengthwise direction on the coaxial inner frame; an outer conductor extending in a lengthwise direction on the coaxial outer frame and facing the inner conductor; and a first resonant frequency adjustment capacitor for connecting one end of the inner conductor in the lengthwise direction and one end of the outer conductor in the lengthwise direction so that the phased array RF coil resonates at an MR operating frequency.

Abstract: A portable magnetic resonance imaging (“MRI”) system that uses static magnetic field inhomogeneities in the main magnet for encoding the spatial location of nuclear spins is provided. Also provided is a spatial-encoding scheme for a low-field, low-power consumption, light-weight, and easily transportable MRI system. In general, the portable MRI system spatially encodes images using spatial inhomogeneities in the polarizing magnetic field rather than using gradient fields. Thus, an inhomogeneous static field is used to polarize, readout, and encode an image of the object. To provide spatial encoding, the magnet is rotated around the object to generate a number of differently encoded measurements. An image is then reconstructed by solving for the object most consistent with the data.

Abstract: A magnetic resonance imaging (MRI) acoustic system includes a magnet; an electro-acoustic transducer that includes a coil through which a current flows so that an attractive force or a repulsive force is generated with respect to the magnet, and a vibrating plate that vibrates in response to the attractive force or the repulsive force; and a controller that controls an intensity of a current input to the electro-acoustic transducer according to a position of the electro-acoustic transducer in a magnetic field generated by the magnet.

Abstract: An electromagnet device which generates magnetic field in the direction perpendicular to the inserting direction of an inspection subject is reduced in size and weight by removing unnecessary arrangement as much as possible. A magnetic resonance imaging device is also provided. The electromagnet device comprises a first coil (31) through which a first circular current (J1) circulates forward, a second coil (32) through which a second circular current (J2) circulates reversely, and a coil group (30) through which a plurality of circular currents (J3-J6) circulate alternately forward and reversely. The first coil (30), the second coil (32) and the coil group (30) are arranged in this order to increase the angle of elevation ? (?1<?2<?3), and a blank region (S) not including the second coil (32) and the coil group (30) exists in the angular region between the angles of elevation ?2 and ?3.

Abstract: Technologies applicable to surface-based NMR measurement are disclosed. A surface probe is positionable at or above a surface of the Earth and adapted to make NMR measurements of shallow or very shallow subsurface volumes. NMR spectrometer components connected to the surface probe are configured to control electromagnetic pulses produced by the surface probe and to record resulting detected NMR signals from the subsurface volume.

Abstract: In one embodiment, a magnetic resonance imaging apparatus includes a gradient coil, a first cooling pipe, and a second cooling pipe. The gradient coil applies a gradient magnetic field onto a subject placed in a static magnetic field. The first cooling pipe is provided in the gradient coil, and circulates a coolant in a certain direction. The second cooling pipe is provided in the gradient coil so as to be in parallel with the first cooling pipe, and circulates a coolant in an opposite direction to a direction in which the first cooling pipe circulates the coolant.

Abstract: In one embodiment, a system includes a gradient coil driver configured to supply electrical signals to a gradient coil of a magnetic resonance imaging system. The gradient coil driver includes an electronic circuit. The electronic circuit includes a first H-bridge circuit electrically coupled to a power source. The first H-bridge includes a plurality of metal-oxide-semiconductor field-effect transistor (MOSFET) switches; and a plurality of diodes electrically coupled in parallel with each MOSFET switch. Each diode of the plurality of diodes is configured to conduct current to cause zero voltage potential across a source and a drain of one of the plurality of MOSFET switches. The first H-bridge also includes a load configured to regulate currents flowing through each of the plurality of diodes and each MOSFET switch of the plurality of MOSFET switches.

Abstract: In one embodiment, an MRI apparatus (20A) includes a data acquisition system (22, 24, 26, 28, 29, 40, 42, 44, 46 and 48), a charge/discharge element (BAT) and a power control unit (52 and 309). The data acquisition system acquires nuclear magnetic resonance signals from an imaging region by performing a scan. The charge/discharge element is a part of an electric power system (304, 308a, 52, BD and BAU) of the MRI apparatus, and is charged with external electric power. The power control unit controls the electric power system in such a manner that at least one unit excluding the data acquisition system is supplied with electric power from the charge/discharge element.

Abstract: A magnetic shield for a field magnet of a magnetic resonance system is provided. A magnet apparatus with a field magnet for a magnetic resonance system with active shielding and a magnetic shield, wherein the magnetic shield forms a hollow body which accommodates the field magnets is also provided. A wall of the hollow body has a first, a second and a third area, which are disposed along the axis. In this case the second area separates the first area and the third area from one another and has a smaller wall thickness than the first and the third area.

Abstract: A magnet system generates a highly stable magnetic field at a sample location. The magnet system has a magnet cryostat housing a first superconducting magnet coil and a second magnet coil co-axial to the first magnet coil. The second magnet coil is short-circuited in a superconducting persistent mode during operation of the magnet system. An external power supply during operation supplies current to the first magnet coil via a current lead thereby generating a first magnetic field at the sample location that fluctuates according to the current noise of the power supply, wherein the second magnet coil is positioned and dimensioned in a way that it inductively couples to the first magnet coil such that it generates at the sample location a second magnetic field that compensates the fluctuations of the first magnetic field.

Abstract: The present embodiments relate to a device and a method for attenuating a high-frequency field of a magnetic resonance tomography system, where at least one attenuation element attenuating high-frequency fields is provided outside a magnetic resonance tomography field of view.

Abstract: A medical apparatus (600) including: a magnetic resonance imaging system (602), a medical device (634), and a slip ring assembly (400, 500) for supplying electrical power to the medical device. The slip ring assembly includes: a cylindrical body (100), a rotating member (402) for rotating the medical device, a first cylindrical conductor attached to the cylindrical body, a second cylindrical conductor (108), a first set of conductive elements (112, 712) connected to the second cylindrical conductor; and a brush assembly (406) comprising a first brush (302) and a second brush (304). The first brush is operable to contact the first cylindrical conductor. The second brush is operable to contact the set of conductive elements. The first and second cylindrical conductive elements overlap at least partially. The second cylindrical conductor is connected to the cylindrical body. The first cylindrical conductor and the second cylindrical conductors are electrically isolated.

Abstract: In a method and device for compensating the insufficient homogeneity of a magnetic field in a magnetic resonance system, the spatial position and size of a basic magnetic field region and at least one additional magnetic field region in a field to be homogenized and determined. An optimization calculation is implemented on the basic magnetic field region and the at least one additional magnetic field region. A homogenized magnetic field at the main magnetic field region and the at least one additional magnetic field region is output according to the result of the optimization calculation.

Abstract: In a method for image data acquisition using a magnetic resonance system, in order to excite nuclear spin signals, a sequence of high-frequency pulses is irradiated into an examination subject while gradients are simultaneously switched for position encoding of the excited nuclear spin signals. The rise times of the gradients used during the sequence are adjusted dynamically with each high-frequency pulse irradiation.

Abstract: Properties of a porous solid sample 19, which may be a core of rock taken from below ground are carried out using apparatus which performs both nuclear magnetic resonance (NMR) and porosimetry measurements. The apparatus has a magnet 11,12 providing a magnetic field and a radio frequency coil 20 for transmitting and/or receiving electromagnetic radiation so as to bring about NMR in the magnetic field, a pressure vessel 14, 15 to hold a sample 19 within the magnetic field, a supply of a non-wetting liquid connected to the vessel, means to apply pressure to the non-wetting liquid to force liquid into pores of the sample 19 means to measure applied pressure of the non-wetting liquid and means to measure volume thereof taken up by the sample. The pressure of non-wetting liquid may be increased in steps, using intruded liquid volume at each step to give a measurement of pore throat size using NMR at each step to give a measure of pore size such as diameter of equivalent sphere.

Abstract: A method for acquiring image data from a plurality of slice locations in a subject with a magnetic resonance imaging (MRI) system is provided. The method includes directing the MRI system to perform a pulse sequence that includes performing a contrast preparation module configured to generate contrast-encoded longitudinal magnetization and an image encoding module configured to acquire image data from multiple slice locations substantially simultaneously. The contrast preparation module generally includes tipping longitudinal magnetization into the transverse plane to produce transverse magnetization, generating contrast-prepared transverse magnetization by establishing an image contrast in the transverse magnetization, and tipping the contrast-prepared magnetization back along the longitudinal axis to produce the contrast-encoded longitudinal magnetization.

Abstract: A magnetic resonance imaging (MRI) system for intracranial vessel wall imaging. The MRI system includes a radio frequency (RF) coil system to irradiate radio frequency (RF) pulses into a region of interest and detect a plurality of RF response signals, and a signal processing unit adapted to analyze the plurality of RF response signals. The RF coil system arranges the RF pulses in a pulse sequence including an excitation pulse and refocusing pulses which induce corresponding flip angles. A minimum flip angle is in the range of 30 degrees to 65 degrees, and a maximum flip angle is in the range of 100 degrees to 150 degrees. The signal processing unit analyzes the RF response signals with a three-dimensional isotropic resolution of 500 cubic microns or less and orders the RF response signals in k-space to enhance contrast between intracranial vessel wall tissue and cerebrospinal fluid or blood.

Abstract: Method for making magnets particularly for the use in MRI scanners, which magnets are three-dimensional and have a tubular wall made of magnetized material, with a closed or open annular shaped cross-section, the tubular wall being composed of individual elements made of magnetized material, the magnetization of each element made of magnetized material having a predetermined direction in the transverse section plane and said directions being determined such to generate a uniform static magnetic field in the cavity of the tubular wall.

Abstract: The present invention provides a permanent magnet arrangement, comprising: a. a mobile permanent magnet grouping; b. a facing plate constructed from ferromagnetic material; c. a an air gap defined by the spacing between said permanent magnet grouping and said facing plate; d. a yoke of predetermined shape formed from magnetically permeable material, said yoke holding said front surfaces of said magnets in a substantially parallel arrangement relative to said facing plate; e. means for individually moving said permanent magnets in said magnet grouping along an axis generally perpendicular to said facing plate; f. means for moving said permanent magnet grouping in a plane generally parallel to said facing plate; wherein a magnetic field within an active volume located in said air gap between said permanent magnet grouping and said facing plate is provided, said magnetic field sufficiently homogeneous for performance of MRI.

Abstract: A method of shimming a superconducting magnet assembly that includes a cryostat and a superconducting magnet configured to be installed in the cryostat. The method includes determining a plurality of field inhomogeneity characteristics of the superconducting magnet while the superconducting magnet is at room temperature and prior to the superconducting magnet being sealed in the cryostat, and installing an initial set of passive shims inside the cryostat while the superconducting magnet is at room temperature, the initial set of passive shims reducing the determined field inhomogeneity characteristics when the superconducting magnet is operating at a normal operational temperature.

Abstract: A magnetic resonance imaging (MRI) system with a thermal reservoir and method for cooling are provided. A cooling vessel for a magnet system of the MRI system includes a first portion containing a helium cryogen in contact with a plurality of magnet coils of an MRI system. The cooling vessel also includes a second portion separate from and fluidly decoupled from the first portion, with the second portion containing a material different than the helium cryogen and having a volume greater than the first portion.

Abstract: A magnetic resonance examination system includes a main magnet with superconducting coils to generate a main magnetic field and a gradient system to apply a gradient magnetic field superposed on the main magnetic field. A cooling system cools the superconducting coils to below their critical superconductivity temperature. A transfer monitor assesses the transfer of energy from the gradient system to the cooling system. The transfer monitor is configured to measure pressure changes in the cooling system. This leads to a simple manner of evaluating the transfer of energy from the gradient coils into the cooling system.

Abstract: Described here are a system and method for designing radio frequency (“RF”) pulses for parallel transmission (“pTx”) applications, and particularly pTx applications in multislice magnetic resonance imaging (“MRI”). The concept of “SAR hopping” is implemented by framing the concept between slice-selective excitations as a constrained optimization problem that attempts designing multiple pulses simultaneously subject to an overall local SAR constraint. This results in the set of RF waveforms that yield the best excitation profiles for all pulses while ensuring that the local SAR of the average of all pulses is below the regulatory limit imposed by the FDA. Pulses are designed simultaneously while constraining local SAR, global SAR, and peak power, and average power explicitly.

Abstract: The invention relates to a state space feedback controller operating in the digital domain for the regulation of the current supply to MRI gradient coils from a multiple-bridge PWM power amplifier. The Pl-controller comprises an integration part (for the integration of the difference between the demand current and the measured gradient coil current) and a subsequent P-controlled system which in turn comprises a delay compensator/stabilizer and a plant. The delay compensator/stabilizer comprises a multi-path feedback loop by means of which its digital output signal is fed back through delay blocks, on the one hand, and through filter units, on the other hand, whereby the filter units model the transfer functions of a gradient coil output filter for the gradient coil voltage and the output current of the amplifier inverter units, respectively.

Abstract: System and methods for designing and using single-sided magnet assemblies for magnetic resonance imaging (MRI) are disclosed. The single-sided magnet assemblies can include an array of permanent magnets disposed at selected positions. At least one of the permanent magnets can be configured to rotate about an axis of rotation in the range of at least +/?10 degrees and can include a magnetization having a vector component perpendicular to the axis of rotation. The single-sided magnet assemblies can further include a magnet frame that is configured to hold the permanent magnets in place while allowing the at least one of the permanent magnets to rotate about the axis of rotation.

Abstract: Systems and methods for self-sealing a coldhead sleeve of a magnetic resonance imaging system are provided. One coldhead sleeve arrangement includes a coldhead sleeve configured to receive therein a coldhead of an MRI system and having an open end. The coldhead sleeve arrangement also includes a sealing member coupled at the open end of the coldhead sleeve and configured in a normally closed position covering the open end.

Abstract: Systems and methods capable of improving acquisition times associated with obtaining diffusion-weighted magnetic resonance imaging data are discussed. In aspects, multiple points in q-space can be sampled in a single repetition time (TR). Acquisition time can be further increased using other techniques, such as a radial raster or compressed sensing.

Abstract: A method for generating a magnetic resonance image includes applying a radio frequency (RF) pulse to a specimen. The method includes modulating a spatially varying magnetic field to impart an angular velocity to a trajectory of a region of resonance relative to the specimen. The method includes acquiring data corresponding to the region of resonance and reconstructing a representation of the specimen based on the data.